The "rise of the celebrity DM" has been pretty weird to watch, yeah? People tune in every week to watch a game they don't get to play in, we've got competitive GMing events, and livestreaming has begun to generate its own products for other people's home games. Niches within niches!
Even weirder is the sometimes-attendant assumption I've seen that posits that DMing is this really hard thing that you need to be a pro to be able to pull off.
I've got a couple assumptions of my own when it comes to DMing: a) like anything else, the more you do it the better you'll get at it, so yeah, maybe you'll be nervous or it will seem hard at first, but you'll get better with practice and b) you don't need advice from "pro DMs," advice from anybody who successfully runs games will either help you out or at least give you another perspective.
In the interest of offering advice and giving my perspective, here are a couple techniques I've been using a lot lately to good effect:
Shining the Spotlight - No matter how carefully you construct your setting, no matter how fully realized your key NPCs are, no matter how grandiose the narrative you deploy, the truth is that there will be things about your game that you think are so cool that your players will just not be interested in. Conversely, they will take an interest in disposable setting elements, minor characters, and relatively unimportant events that you never intended to be focal points. My advice: keep an eye out for the things that pique your players' interest and catch their imagination, then give them more of that. Shine the spotlight on the things that grab them.
I can give a concrete example of this: in my Krevborna game, the players took an NPC to the mysterious Church of St. Othric so she could have horrible curse lifted. I intended the faith of St. Othric to appear in that one adventure--it was more or less a throwaway. Except...the players got really interested in St. Othric, so I threw more St. Othric at them as the campaign progressed: they adventured into the saint's tomb, a player's paladin character devoted himself to the saint, and the group became heavily involved in re-establishing the faith's knightly order throughout the setting. Now it's a major part of the setting that's really cool, all because I picked up on what had grabbed their attention and ran with it. I got a ton of mileage out of paying attention to their interest and moving the spotlight to accomodate it.
In Media Res - Everybody knows that "starting in media res" means "starting in the middle of things" in fiction, right? Well, it's a technique you can use it in your games too. You don't have to start your sessions with "You all meet in a tavern"; why not start your game with the characters in the thick of some treacherous situation? Once the situation is resolved work backwards to establish how they got in that situation and what they're doing.
I've been starting in media res a lot in my Google Hangouts games because we have limited time and it turns out that dickering around with negotiating a fee to go on an adventure is boring every time. Now I just start with explaining what the job or task at hand is, and let the players steer the ship from there. It's cleaner, makes better use of our time playing together, and gets the game moving faster and in a more focused direction.